Midterm Exam Database Design Oracle 1 Keys [PDF]

Zitiervorschau

Midterm Exam Database Design Oracle Section 1 (Answer all questions in this section) 1. The main subject areas taught by the Oracle Academy are: (1) Points Data Modeling, SQL, and PL/SQL (*) Computer Repairs Database performance tuning Systems programming and computer architecture

Mark for Review

2. What is the difference between "information" and "data"? Mark for Review (1) Points Data turns into useful information. It is stored in a database and accessed by systems and users. (*) Information and data have no differences - they are two words for the same thing. Information is held and understood only by users. Data is held and understood only by users. 3. Consider your school library. It will have a database with transaction details of the books that are borrowed by students. Is the total number of books out on loan in one given month considered Data or Information? Mark for Review (1) Points Data Information (*) Both Neither 4. Changes in computing have affected many of our day-to-day activities. Are all of the following activities examples of this change? Yes or No? In the past you used to use the phone system to call directory assistance to get a phone number. Today you can use your PC to look up a phone number online. In the past you used to have to go to the shoe store to buy shoes. Today you can use your PC to order shoes online. In the past you had to use your PC to send a person an email. Today you can use your phone to send a text message. Yes (*) No 5. The overall mission of the Oracle Corporation is to use the internet and fast processing servers to build its own network. Mark for Review True False (*) 6. In the grid computing model, resources are pooled together for efficiency. True or False? Mark for Review True (*) False 7. Personal computers (PCs) have been in existence since 1950. True or False? Mark for Review (1) Points True False (*)

8. Entities are transformed into Tables during the Database Design process. True or False? Mark for Review True (*) False 9. Databases are used in most countries and by most governments. Life, as we know it, would change drastically if we no longer had access to databases. True or False? Mark for Review (1) Points True (*) False 10. Oracle was one of the first relational database systems available commercially. True or False? Mark for Review (1) Points True (*) False Section 2 (Answer all questions in this section) 11. Data models show users the data that their Physical Model will contain. True or False? Mark for True (*) False 12. Data models are drawn to show users the actual Data that their new system will contain; only Data listed on the Diagram can be entered into the Database. True or False? Mark for Review True (*) False 13.

An ERD is an example of a Physical Model. True or False? True False (*)

Mark for Review

14. Documenting Business Requirements helps developers control the scope of the system and prevents users from claiming that the new system does not meet their business requirements. True or False? Mark for Review (1) Points True (*) False 15.

Which of the following attributes is suitable to be a Unique Identifier? Address Last name First name Social Security Number (*)

Mark for Review

16. In the following statements, find two good examples of ENTITY: Instance. (Choose Two) for Review BOOK: Biography of Mahatma Gandhi (*) VEGETABLE: grows TRAIN: runs DAIRY PRODUCT: milk (*)

Mark

17.

Which of the following is an example of a volatile attribute? Mark for Review Hire Date Name Date of Birth Age (*)

18. Which of the following entities most likely contains valid attributes? (Choose two) Review (Choose all correct answers) Entity: Home. Attributes: Number of Bedrooms, Owner, Address, Date Built (*) Entity: Pet. Attributes: Name, Birthdate, Owner (*) Entity: Car. Attributes: Owner Occupation, Owner Salary, Speed Entity: Mother. Attributes: Name, Birthdate, Occupation, Start Date

Mark for

19. All of the following could be attributes of an ENTITY called PERSON, except which one? Mark for Review (1) Points Gender Natacha Hansen (*) Weight Haircolor 20.

Which of the following are examples of ENTITY: Instance ? (Choose Two) Mark for Review (Choose all correct answers) MEAT PRODUCT: Lettuce TRANSPORTATION METHOD: Car (*) BODY PART: Larry Ellison ANIMAL: Dog (*)

21. An Entity Relationship model is independent of the hardware or software used for implementation. True or False? Mark for Review (1) Points True (*) False 22. Which of the following statements are true about ERD's? (Choose Two) Mark for Review (1) Points (Choose all correct answers) You should not model derivable data. (*) A piece of information can be shown multiple times on an ERD. A piece of information should only be found in one place on an ERD. (*) All data must be represented on the ERD, including derived summaries and the result of calculations. 23.

Which of the following can be found in an ERD? (Choose Two) Attributes. (*) Instances. Entities. (*) Tables.

Mark for Review

Section 3 (Answer all questions in this section) 24. When reading a relationship between 2 entities, the relationship is read both from left to right and right to left. True or False? Mark for Review True (*) False

25.

Relationship names are not shown on an ERD. True or False? True False (*)

Mark for Review

26.

Which symbol is used to show that a particular attribute is mandatory? o * (*) # &

Mark for Review

27. Matrix Diagrams show Optionality and Cardinality of the ERDs they document. True or False? Mark for Review True False (*) 28.

Matrix Diagrams are developed BEFORE the ERD. True or False? True (*) False

Mark for Review

29.

What are the three properties that every relationship should have?

Mark for Review

Transferability, degree, name Name, optionality, cardinality (*) Name, optionality, arcs A UID bar, a diamond, an arc 30. Which of the following are used to show Cardinality on an ERD? (Choose two) Review

Mark for

Dashed line. Single toe. (*) Crow's foot. (*) Solid line. 31.

Relationship Cardinality is important. True or False? Mark for Review True (*) False Section 4 (Answer all questions in this section) 32.

Why is it important to identify and document business rules? Mark for Review It allows you to create a complete data model and then check it for accuracy. (*) It allows you to improve the client's business. It ensures that the data model will automate all manual processes. None of the above

33.

Why is it important to identify and document structural rules?

Mark for Review

Ensures we know what data to store and how that data works together. (*) Ensures nothing. There are no benefits to be gained from documenting your Structural Business Rules. We need to concentrate on the Procedural Business Rules only. Ensures we know what processes are in place and how to program them. All of the Above.

34. How should you handle constraints that cannot be modeled on an ER diagram? Review Explain them to the users so they can enforce them Always let the network architect handle them List them on a separate document to be handled programmatically (*) All constraints must be modeled and shown on the ER diagram

Mark for

35. A new system would have a mixture of both Procedural and Structural Business Rules as part of the documentation of that new system. True or False? Mark for Review True (*) False 36.

All ER diagrams must have one of each of the following: (Choose two)

Mark for Review

At least one supertype and subtype One or more Entities (*) Relationships between entities (*) Arcs 37. A subtype is drawn on an ERD as an entity inside the "softbox" of the supertype. True or False? Mark for Review True (*) False 38. A subtype is shown on an ERD as an entity with a one to many relationship to the supertype. True or False? Mark for Review True False (*) 39. A subtype can have a relationship not shared by the supertype. True or False? Review True (*) False

Mark for

40. All instances of a subtype may be an instance of the supertype but does not have to. True or False? Mark for Review True False (*) Section 5 (Answer all questions in this section) 41. If the same relationship is represented twice in an Entity Relationship Model, it is said to be: Mark for Review Removable Resourceful Redundant (*) Replicated 42. What uncommon relationship is described by the statements: "Each DNA SAMPLE may be taken from one and only one PERSON and each PERSON may provide one and only one DNA SAMPLE" Mark for Review (1) Points Many to Many Mandatory One to Many Optional One to Many Mandatory One to One Optional (*)

43. If two entities have two relationships between them, these relationships can be either _____________ or _____________ . Mark for Review Redundant or Required (*) Replicated or Required Resourced and Really Good Redundant and Replicated 44. Which of the following pairs of entities is most likely to be modeled as a M:M relationship? Mark for Review TREE and BRANCH PERSON and FINGERPRINT TEACHER and SUBJECT AREA (*) CAR and WHEEL 45. When you resolve a M:M by creating an intersection entity, this new entity will always inherit: Mark for Review The UID's from the entities in the original M:M. The attributes of both related entities. A relationship to each entity from the original M:M. (*) Nothing is inherited from the original entities and relationship. 46. When you resolve a M:M, you simply re-draw the relationships between the two original entities; no new entities are created. True or False? Mark for Review True False (*) 47. If an intersection entity is formed that contains no attributes of its own, its uniqueness may be modeled by Mark for Review Creating new attributes. Barring the relationships to the original entities. (*) Placing the UID attributes from the original entities into the intersection entity. None of the above. 48. be:

If a relationship can NOT be moved between instances of the entities it connects, it is said to Mark for Review Mandatory Transferable Optional Non-Transferable (*)

49. A non-transferable relationship means the relationship is manatory at both sides. True or False? Mark for Review True False (*) 50. A non-transferable relationship is represented by which of the following symbols? Mark for Review (1) Points Circle Triangle Heart Diamond (*)